Improvement in the manufacture of hollow rivets



MELLEN BRAY, OF NEWTON, MASSACHUSETTS.

IMPROVEMENT IN THE MANUFACTURE OF HOLLOW RIVE TSQ Specification-forming part of Letters Patent No. 140,851, dated July 15, 1873; application filed March 17, 1873.

To all whom it may concern:

Be it known that I, MELLEN BRAY, of Newton, in the county of Middlesex and State of Massachusetts, have invented an 1mproved Hollow Rivet, and a process of making the same, of which the following is a specification:

My improved rivet is formed by first making a piece of tube with a closed end, of the proper length to make both the body of the rivet and the head, by drawing up the same from a piece of sheet metal by a mode of operation similar to that by which articles of a cylindrical tubular form are 'made, as is set forth in the Letters Patent reissued to me January 28, 1873, for dies for forming ing the head much larger than could otherwise be made. The projecting portions of the tubes are then upset bya die coming down upon it, which first causes the sides to bulge out, and then to be flattened down upon the lower die, and shaped into the usual form of head. This is very important in making rivets to be used in leather, cloth, and other flexible materials, where a small head would be liable. to be drawn through.

When this supplementary thickness of tube to form the head is placed within the main tube the outer end of it need not be closed; but in practice I have found it easiest, with my present machinery, to produce the enlarged head by placing the supplementary piece of tube upon the outside; but I have alsov made rivets with the supplementary tube inside with complete success.

Figure 1 is the closed tube from which the rivet is to be formed, shown in section. Fig. 2 is the supplementary tube, which is placed upon Fig. l tofurnish the material to form an enlarged head. .Fig. 3 is a section through the forming-dies with the tubes placed together in them and in the position to be upset. Fig. 4 is a section of the tube with the supplementary tube placed inside. Fig. 5 is a section of the rivet ready for use and Fig. 6 shows its application to use.

A is the piece of tube from which the main body of the rivet is formed. 13 is the supplementary piece to form the head, which is placed on the outside of A, as is seen in Fig. 3 5 and B is the supplementary tube, placed inside of A, as seen in Fig. 4 O 0 is the holding-die, made in two parts, one of which, G, is fixed; and the other, C, is movable, so as to open to release the rivet after it is formed. They are held together by devices not shown; and the part 0 is pressed away from the fixed part 0 by the spring D. E is the bed for the die 0 O, to which the fixed part 0 is held in a fixed position by the dewel-pin F. The opening in the die 0 G is large enough to allow the tube A to be slipped in freely. G is a mandrel of the proper size to fit the inside of the tube A, and is made to slide vertically through the bed E, and is concentric with the hole in the dies. It sets in a guide-piece, H, and is held up by the spring I. I

When the several parts are in the position shown in Fig. 3 the movable heading-die J is brought down upon the projecting portions of the tubes until the parts are brought to the positions shown by the dotted lines, which produces the rivet shown in Fig. 5. The action of the heading-die is to first cause the projecting portions of the tubes A and B to bulge out laterally, and then to be flattened into the head, as is shown.

When the supplementary tube is placed inside, as is shown in Fig. 4, the mandrel Gr extends upward to meet the lower end of the tube B, and remains fixed at about the height of the top of the die 0 G.

The rivets are to be clinched by a punch in the manner similar to that now employed to clinch common eyelets, as is seen in Fig. 6.

I claim I 1. In the process of forming 2b hollow riv 2. The hollow rivet, formed by the pro et, by upsetting the end portion of a closed cess herein described, as a new manufacture. tube, the combination, with the closed end Executed February 24, 1873.

of the. tube, of a secondary or supplement- MELLEN BRAY. ary piece of tube, to be upset to furnish addi- Witnesses: tional material to form the head of the rivet, ALBERT E. DOWNS,

substantially as described. WM. 0. HIBBARD.' 

